Feline Information Bulletin Cornell Feline Research Laboratory Number 3, February 1978 nonexistent for the cat. Bacterial skin always cause one to suspect a Feline Skin diseases of the cat include abscessation- concurrent feline leukemia virus cellulitis, atypical mycobacterial (FeLV) infection. FeLV infection may Disorders infection, dermatophilosis (strepto- be associated with suppression of the thricosis), actinomycosis, nocardiosis, cat's immune responses and predis­ Danny W. Scott, D.V.M., and tuberculosis. Only the first two pose it to recurring infections of d .a .c .v .i .m . will be discussed here. many organ systems. Prevention of AC would necessi­ Abscessation-cellulitis (AC). AC is one tate avoidance of cat fights; it has of the most common of feline skin been shown that castration of male Feline dermatology is in its infancy; disorders and may affect any breed, cats, even in adulthood, is 80 to 90 much information has been gathered sex (but especially intact males), or percent effective in preventing in the last five to ten years. This age. AC is almost always a secondary fighting. bulletin will present a brief overview occurrence to bites and scratches of the current status of some of the from cat fights, the most common Atypical mycobacterial infection (FL, more common feline skin disorders areas affected being the face, limbs, leprosy). Feline leprosy (FL) is caused and attempt to point out where base of the tail, and back. The bacteria by bacteria that are thought to be research is sorely needed. In a few involved are invariably those that mainly soil and water inhabitants and skin disorders, such as abscesses and normally reside in the cat's mouth cause infection by wound contamina­ nutritional steatitis, the cause, (Pasteurella multocida, Streptococcus spp., tion. There are apparently several diagnosis, treatment, and even pre­ Fusiformis spp.). species of mycobacteria involved. A vention are well established. In other An abscess is an infection charac­ cat of any breed, sex, or age may be disorders, such as dermatophytosis terized by a focal accum ulation of pus. affected. and flea allergy, the cause and Cellulitis is a diffuse infection of the Signs of FL include one to multiple diagnosis are fairly straightforward, skin characterized by swelling, pain, nonpainful, nonpruritic (nonitching) but many questions about treatment and failure to "come to a head." Signs nodules (tumors) in the skin that and prevention remain unanswered. of AC are quite variable, from the frequently ulcerate. These lesions In yet another group of cutaneous classic abscess (swelling, heat, pain, may occur anywhere on the body. diseases, such as the eosinophilic eventual drainage) to swelling with-, Regional lymphadenopathy may be granuloma complex and feline endo­ out heat or pain to severe pain present, but the cat usually appears crine alopecia, diagnosis is easy and without much swelling. Affected cats healthy otherwise. control is possible with maintenance will often have fevers, elevated white Diagnosis is made by history, drug regimes, but little is known blood cell counts, depression, leth­ physical, and surgical biopsy. The concerning cause and prevention. argy, and lack of appetite. AC must be different mycobacteria involved are treated with respect, as more serious very difficult to culture, and culturing Bacterial Skin Diseases infectious sequelae may include requires special laboratory tech­ Normal skin is a good culture medium pyothorax, otitis media, osteomy­ niques. Treatment is by surgical for bacteria. Bacteria are normally elitis, sinusitis, rhinitis, septic removal. To date, drug therapy with found on the surface of the skin and arthritis, and bacteremia. various antileprosy and antituber­ m the outer portions of hair follicles Diagnosis is usually made by culosis agents used in man has been down to the depth of sebaceous gland history, physical examination, and disappointing in the cat. ducts. Although knowledge concern­ surgical drainage. Treatment usually Much remains to be learned about ing normal and abnormal skin bac­ includes surgical drainage and topical FL. It has only been recently recog­ teria in m an is quite advanced, it is and systemic antibiotics. Recurrent, nized in the United States, and minimal for the dog and virtually chronic, or poorly healing AC should questions as to the exact mode of transmission, the number and types lesions or the entire body), topical indirect contact and may also produce of mycobacteria involved, and the fungicide dips (such as lime sulfur or transient skin disease in humans. No relationship to murine and human captan) once weekly, and griseofulvin breed, sex, or age predilections of leprosy must be answered. orally. Such therapy is continued these parasites are known. until clinical or mycologic cure is Signs of C are quite variable and in­ achieved (four to twelve weeks). Gris­ clude seborrhea sicca, miliary eczema, Fungal Skin Diseases eofulvin should not be given to preg­ and the asymptomatic carrier. In the Fungi may be responsible for super­ nant queens, as teratogenicity (birth case of the cat with asymptomatic ficial (as is most common) or deep defects) may result. Treatment of infection, the only clue may be the infections of the skin. Fungal skin exposed animals should include iso­ red, itchy dermatitis in its owner. diseases of the cat include dermato- lation, dips, and griseofulvin for two Diagnosis includes history, physi­ phytosis, pityrosporiasis, sporotri­ weeks. If no signs of disease have cal examination, skin scrapings, and chosis, mycetoma, phaeohyphomy­ occurred, drug therapy may be fecal flotation. Treatment includes (l) cosis, blastomycosis, coccidioidomy­ stopped and isolation continued. the affected cat (parasiticidal dips, cosis, cryptococcosis, and histo­ Treatment of the environment in­ shampoos, or powders, weekly for plasmosis. Only dermatophytosis will cludes weekly thorough vacuuming three to four weeks), (2) in-contact be considered here. and emptying or discarding vacuum animals (same), and (3) the environ­ bag and weekly fungicidal washings ment (thorough vacuuming, parasiti­ Dermatophytosis (D, dermatomycosis (iodophors, formaldehyde, Clorox, cidal washes, weekly for three to four tinea, ringworm). D is one of the more etc.) where feasible (floors, walls, weeks). Parasiticidal agents contain­ common feline skin disorders and is kennels, etc.). Every infected hair that ing almost any of the organophos- caused by a number of fungi, the most falls off the cat and comes to rest in phates or the chlorinated hydro­ common of which are Microsporum the environment is a source of carbons are to be avoided in cats. canis, Microsporum gypseum, and Tri­ infection for over a year. Prevention requires avoiding contact chophyton mentagrophytes. M. canis is the Important questions concerning with infected animals, which may be most common cause of feline D, and therapy and prevention remain. problematical in the outdoor cat. the main source of infection is carrier There is currently much confusion cats; M. gypseum is found in soil, and T. and concern over what the effective Otodectic mange (OM, ear mites). O M is mentagrophytes is carried by rodents. dose and frequency of administration caused by the mite Otodectes cynotis. These fungi are transmitted by direct of griseofulvin in cats should be. This mite infects cats and dogs and and indirect contact (environment, Preliminary studies in other animal may produce transient dermatitis in fomites, air, etc.) and are readily species suggest that vaccination humans. OM is quite contagious, by passed from animal to animal, and against D may be beneficial. To date, direct or indirect contact. from animal to man. A cat of any prevention is possible only by avoid­ Signs of OM include (l) otitis breed, sex, or age (but especially ing infected animals and humans. externa (external ear infection), with young cats) may be affected. resultant head shaking, ear scratch­ Signs of D are extremely variable, ing, creation of sores and ulcers which is often confusing and mis­ around the head and ears, and a leading. Skin lesions vary from the Parasitic Skin Diseases discharge from the ears, which may classic ringworm (circular area of Parasites are one of the more vary from a coffee-ground appear­ alopecia, scaling, crusting, with or common causes of skin disease in the ance to a waxy brown; (2) seizures without inflammation) to pigmentary cat. These parasites may be on the (unusual severe cases); and (3) the changes of skin or hairs to broken skin (ectoparasites) or within the asymptomatic carrier. hairs to seborrhea sicca ("dandruff") body (endoparasites). Parasitic skin Diagnosis includes history, physi­ to miliary eczema to the asympto­ diseases in the cat include cheyletiel- cal, otoscopic examination, and matic carrier. Lesions may occur losis, demodectic mange, trombicu- microscopic examination of ear anywhere but are especially common lidiasis (chiggers), otodectic mange swabs. Treatment must include (l) on the face, head, and extremities. (ear mites), fleas, pediculosis (lice), the affected cat (miticidal otic prepa­ Diagnosis is by history, physical, ticks, cuterebriasis (grubs), myiasis rations, twice weekly for four weeks, and fungal culture. The Woods light (maggots, "fly-strike"), and intestinal and flea powder, total body, once (ultraviolet light) examination and parasitism. Only a few of these will be weekly for four weeks); and (2) in­ KOH preparation are quick, easy, discussed here. contact animals